Dipolar aprotic solvent system for polymerization of bis-(alpha-haloalkyl) aromatic compounds in the presence of a coupling agent



United States Patent 3,345,332 DIPOLAR APROTIC SOLVENT SYSTEM FORPOLYMERIZATION OF BlS-(a-HALOALKYL) AROMATIC COMPOUNDS IN THE PRES- ENCEOF A COUPLING AGENT John M. Hoyt and Charles E. Frank, Cincinnati, andKarl Koch, Norwood, Ohio, assignors to National Distillers and ChemicalCorporation, New York, N.Y., a corporation of Virginia No Drawing. FiledApr. 2, 1964, Ser. No. 356,928 28 Claims. (Cl. 260-47) This inventionrelates to a new and improved polymerization process for the preparationof mixed aliphaticaromatic polymers and copolymers. More specifically,the invention pertains to the coupling of aromatic compounds having atleast two substituents, in each of which there are one to three halogenatoms bonded to that substituent carbon atom attached to the aromaticring, in the presence of dipolar aprotic solvent systems which dissolvethe reactants. A further aspect of this invention resides in thepreparation of certain novel polymeric products.

It has recently been found that bis-(a-haloalkyDaromatic compounds canbe polymerized, in solution, to the correspondingpoly(arylenedialkylene) polymers at temperatures less than about 300 C.in the presence of a lower valent transition metal salt, e.g. chromoussulfate. U.S. patent application Ser. No. 357,279, entitled,Polymerization Process. It has also recently been found that copolymericproducts can be produced by reacting mixtures of one or morebis-(u-haloalkyl)aromatic compounds with certain olefinic compounds atthese low temperatures with the same lower valent transition metalsalts. U.S. patent application Ser. No. 357,303, entitledcopolymerization Process. Both of these processes are preferably carriedout in the presence of an inert atmosphere, e.g. nitrogen, to avoidoxidation of the lower valent transition metal salt. The processes alsocall for dissolving the lower valent transition metal salt in ahydroxylic solvent such as water, methanol, ethylene glycol and thelike. It has been found important to employ a solvent for thebis-(u-haloalkyl)aromatic compounds and for the olefinic compounds. Whenthe latter solvents are employed, they were required to be miscible withthe hydroxylic solvent used in conjunction with the lower valenttransition metal salt. Typical examples of such miscible solvents areacetone, p-dioxane and the like. In another recent development it wasfound that increased yields and higher molecular weight polymer andcopolymer products could be achieved by employing in conjunction Withthe hydroxylic solvent for the lower valent transition metal salt orcoupling agent an organic solvent for the bis-(a-haloalkyl)aromaticcompounds and the olefinic compounds, if utilized. One essentialcharacteristic of the organic solvent is that it be substantiallyimmiscible with the hydroxylic solvent. Although the preferred organicsolvent was found to be decalin, other possible organic solventsincluded cyclohexane, benzene, toluene, xylene, o-dichlorobenzene, lowermolecular weight alkanes as well as aromatic and aliphatic ketones,esters and ethers. U.S. patent application Ser. No. 356,943, entitledImproved Polymerization Process for Aromatic Compounds.

The presence of hydroxylic solvents in the above-describedpolymerization and copolymerization processes has been found to resultin some undesirable limitations. For one thing, the use of aproton-releasing solvent, i.e. a hydroxylic solvent, has in some casesresulted in the occurrence of hydrogen transfer reactions which preventhigh molecular weight polymer formation as well as the production ofundesirable by-products. In addition, it has been generally found thatonly orthoand para (phenylenedialkylene) polymers have been obtained'ice when hydroxylic solvents are present in the reaction mixtures. Ithas also been found difficult to prepare polymers and copolymers whereina-haloalkyl groups exist on isolated, non-conjugated rings in thebis-(u-haloalkyDaromatic compounds. It has likewise been difficult toprepare useful polymers and copolymers wherein the coupling occursthrough a,a-dihaloalkyl,a,u,a-trihalomethyl or acyl halide groups bondedto aromatic nuclei because of the hydrolytic instability of certain ofthese groups and because of the difliculty in fabricating the polymerformed.

One object of the present invention is to provide new and improvedpolymerization and copolymerization processes which avoid thelimitations of the previously proposed processes.

Another object of the present invention is to provide new and improvedpolymerization and copolymerization processes which result in theformation of metaas well as orthoand para(diphenylenedialkylene)polymers and copolymers.

A further object of the present invention is to provide new and improvedpolymerization and copolymerization processes which can utilizebis-(a-haloalkyl)aromatic compounds containing a-haloalkyl groups onisolated, non-conjugated rings.

A still further object of the present invention is to provide new andimproved polymerization processes which can utilize related aromaticcompounds containing at least two substituents, selected from the groupconsisting of a-haloalkyl, a,u-dihaloalkyl, a,a,u-trihalomethyl radicalsand acyl halide radicals.

An additional object of the present invention is to provide certainnovel polymeric products.

These and other objects of the present invention will become readilyapparent from the ensuing description and illustrative embodiments.

In accordance with the present invention it has now been found that oneor more aromatic compounds having at least two substituents, in each ofwhich there are one to three halogen atoms bonded to that substituentcarbon atom attached to the aromatic ring, or a mixture of one or moresuch aromatic compounds with certain olefinic compounds, dissolved in adipolar aprotic solvent, can be reacted in the presence of an anhydrouslower valent transition metal salt, which is also dissolved in a dipolaraprotic solvent, to prepare highly desirable polymers and copolymers. Byutilizing the dipolar aprotic solvent system it is possible not only toprepare orthoand para-(phenylenedialkylene) polymers but also meta-(phenylenedialkylene) polymers as well as polymers and copolymers frombis-(a-haloalkyl) aromatic monomers in which the a-haloalkyl groups arein different, nonconjugated aromatic rings, as well as polymers andcopolymers derived by coupling aromatic compounds containinga,a-dihaloalkyl, and a,a,a-trihalomethyl, and acyl halide groups bondedto aromatic nuclei.

Dipolar aprotic solvents have been defined as solvents with dielectricconstants greater than 15 which, although they may contain hydrogenatoms, cannot donate suita U polymerized, the olefinic compound or vinylmonomer when employed, and the lower valent transition metal salt orcoupling agent.

The preferred lower valent transition metals are divalent chromium,divalent vanadium and trivalent titanium; the use of divalent chromiumsalts is especially preferred. It was also found preferable to employ atransition metal salt with an anion of a strong acid, i.e., an acidwhich in N aqueous solution has a pH of less than about 2. Such anionsinclude the sulfate, chloride, the phosphate and the like. The use ofthe chloride anion was found to be preferred for the purposes of thisinvention, and for purposes of illustration the invention will bedescribed more particularly hereinafter in connection with the use ofchrornous chloride as the lower 'valent transition metal salt. Althoughthe foregoing transition metals have been found to be especially usefulin carrying out the polymerization process of this invention, otherpossible lower valent transition metals may be selected from the groupconsisting of hafnium, zirconium, columbium, tantalum, molybdenum,tungsten, manganese, iron, ruthenium, osmium, cobalt, rhodium,

iridium, nickel, palladium, platinum and copper.

In general, the concentration of the lower valent transition metal saltin the reaction mixture will be within the range of about 0.05 to 4moles, and preferably about 0.1 to 1 mole per liter of reaction mixture.

One of the starting materials for the polymerization process of thisinvention is an aromatic compound having at least two substituents, ineach of which there are one 7 there are from one to three halogen atomsbonded to that substituent carbon atom which is attached to the aromaticring, may be at any position relative to each other in the same ring orin different aromatic rings, it is preferred that they be in positionsortho or para to each other in the same aromatic ring. The halogen atomscontained in the said substituents are selected from the groupcomprising fluorine, chlorine, bromine and iodine, as well as mixturesthereof. The substituents themselves, in addition to the halogen atoms,may contain about one to twenty carbon atoms and may be either straightor branched chain. However, for most purposes the substituents willcontain about one to eight carbon atoms.

In general, the structural formula for the starting material will be:

wherein X and X are fluorine, chlorine, bromine or iodine, and the X andX may be the same or different, R R R and R are univalent radicals suchas bromine, iodine, hydrogen, trifluoromethyl, a lower alkyl grouphaving from 1 to 6 carbon atoms either straight or branched chain, arylgroup having 6 to 10 carbon atoms, substituted aryl, or may be replacedin pairs by a divalent radical, e.g., R and R and R and R may representtwo carbonyl oxygen radicals.

The R substituents may be the same or different.

The subscripts n and m are small positive integers and it is preferredthat n and m both be equal to one because it is generally found thatcrosslinked insoluble polymers are produced when (n+m) is greater than2. Such materials are virtually impossible to fabricate by knownmethods. However, in one embodiment of the process of this invention,the polymer may be formed in situ in and on a suitable substrate. Insuch cases even essentially crosslinked polymeric materials, whenproduced in situ often exhibit sufficient flow at elevated temperaturesand under sufficient pressure to be capable of combining with thesubstrate to form a composite article relatively continuous in natureand impervious to gas and liquids. In such cases (n+m) may be greaterthan two and is limited ultimately only by the number of XCR R and -CR RX' substituents for which there are positions available in the aromaticconstituent Ar.

Ar is the aromatic substituent which is defined above, and the Arsubstituent may be further substituted on the ring, and in variouspositions, with chlorine, bromine, iodine, cyano, nitro, carboxy orcarboalkoxy groups, alkyl groups having from 1 to 20 carbon atoms, oralkoxy groups having from 1 to 20 carbon atoms. It will be understoodthat these alkyl and alkoxy groups may also be either straight orbranched chain.

By utilizing such starting materials the mixed aliphatic-aromaticpolymers prepared in accordance with the process of this invention willcontain the following recurring units with the various substituents asdefined above. However,

it is understood that when R R R and R are fluorine,

a,a'-dichloro-p-xylene a,a'-dibromo-m-Xylene a,ot'-dibromo-o-xylene1,4-bisix-chloroi'sopropyl) benzene 2,5-bischloromethyl) -p-xylenea,a-dichloro-2-nitro-p-xylene (1,06-dichloro-4-carbornethoxy-o-xylenea,u'-dichloro-a,a'-diphenyl-p-xylene 2,5 -bischloromethyl) -1,4-dimethoxybenzene 4,5 -bis- (chloromethyl -l ,2-dimethoxybenzene 4,5-bis-. chloromethyl -o-xylene a,a',2,3,5,6-hexachloro-p-xylene1,4-bisot-chloroisopropyl) benzene 1,3 -bis- (a-chloroperfluoroisopropyl-2,4,5,6-tetrafiuorobenzene a,rid-2,4,5,6-hexachloro-m-xylene1,4-bisdifiuorochloromethyl -2,3,5 ,G-tetrafiuorobenzene 1,2-bis-(difluoro chloromethyl) -2,3 ,5 ,6-tetrachlorobenzene1,4-bis-(cl1loromethy1 naphthalene 5,8-bischloromethyl tetralin 5,6-bis- (chloromethyl) indane bischloromethyl durene 1,4-dibromo-1 ,2,3,4-tetrahydronaphthalene 1,4-dichloro-1,4-dihydronaphthalene1,4-dichloro-2,3 -diacetoxy-1,2,3 ,4-tetrahydronaphthalene 1,3-dichloroindane 2,5 -bischloromethyl thiophene 2,3 -bischloromethyl)furan 2,5 -bischloromethyl furan 3 ,4-bischloromethyl pyrrole 5 ,8-bis(chloromethyl) quinoline 5,8-bis- (chloromethyl isoquinoline 5,6-bischloromethyl quinoline 6,7-bischloromethyl -4-chloroquino1ine 9,IO-bis- (chloromethyl) anthracene 9,10-bis-(chloromethyl)-l-methylanthracene 9,10-bis-(chloromethyl)phenanthrene4,4-bischloromethyl) diphenyl ether 2,4-bis- (chloromethyl)diphenylether 3,3'-bis-(chloromethyl) diphenyl ether4,4-bis-(difluorochloromethyl)-2,2,3,3,5,5,6,6'-0ctafiuorodiphenyl ethera,a,a,a,a,a-hexachloro-p-Xylene oz,oc,a,oc',ot',oc'-hCXaChlOIO-InXy16n6a,a,a,m'-tetrachloro-pxylene l,2,4,5-tetrakis (bromomethyl) benzene1,4-bis-(a,u-dichlorobenzyl)benzene 4,4'-bis(a,u-dichloromethyl)diphenylether 4,4--bis-(a,a-dichlorobenzyl)diphenyl ether terephthaloyldichloride isophthaloyl dichloride 4,4-oxybis- (benzoyl chloride) Theolefinic compounds which may be employed in conjunction with thehalogen-containing aromatic compounds to prepare various copolymers willhave the following structural formula wherein R is selected from thegroup consisting of hydrogen, a cyano radical, and an aryl group havingfrom 6 to 10 carbon atoms.

R is selected from the group consisting of hydrogen, a lower alkyl grouphaving from 1 to 6 carbon atoms, and a COOR radical wherein R is a loweralkyl group having from 1 to 12 carbon atoms.

R, is selected from the group consisting of hydrogen, a CN radical, a Nradical, a COOH radical, a lower alkyl group having from 1 to 6 carbonatoms, a CH COOR radical and a COOR radical wherein R is a lower alkylgroup having from 1 to 12 carbon atoms, a CONH radical, a CONHR' orCONR' radical wherein R is a lower alkyl group having from 1 to 6 carbonatoms, or an aryl group having 6 to 10 carbon atoms.

Illustrative vinyl comonomers include:

styrene p-chlorostyrene methyl acrylate methyl methacrylate acrylamideN,N-dimethyl acrylamide acrylonitrile diethyl itaconate ethyl cinnamatecinnamonitrile fumaronitrile omega-nitrostyrene When a comonomer isemployed in preparing copolymeric products, the mole ratio of thehalogen-containing aromatic compound to the olefinic comonomer willgenerally range from about 100:1 to 1:100, and preferably about 100:5 to:100.

The polymerization and copolymerization processes of this invention areadvantageously carried out within a temperature range of about 30 to 300C., preferably about 0 to 200 C. The pressure under which the reac tionmay be carried out can vary from about 1 to 1000 p.s.i.a., and it ispreferably autogenous. For most purposes it is preferred to carry outthe polymerization and copolymerization reactions in an inert atmosphereto prevent oxidation of the lower valent transition metal salt.Illustrative inert gases include nitrogen, argon, carbon dioxide,methane, helium and mixtures thereof, and the like. Although thereactions will proceed without agitation or stirring, some degree ofagitation during the polymerization or copolymerization reaction hasbeen found helpful. The time period for carrying out the reactions ofthis invention may vary over a wide range depending in part on otheroperation conditions employed. In general, however, thetime period mayrange from about 1 minute up to about 48 hours with the preferred timebeing about 2 to 4 hours. The processes may also be carried in acontinuous or semi-continuous basis. For economic reasons, the lowervalent transition metal salt, which becomes oxidized during the courseof the reaction, is recovered and reduced to its original lower valentstate and recycled. Alternatively, continuous in situ regeneration ofthe lower valent transition metal salt is possible by maintaining anexcess of reducing metal, e.g., zinc or chromium, in contact with thetransition metal solution during the polymerization.

In accordance with the process of this invention, aromatic compoundshaving at least two substituents, in each of which there are one tothree halogen atoms bonded to that substituent carbon atom attached tothe aromatic ring, or a mixture of one or more such aromatic compounds,or a mixture of one or more such aromatic compounds and a vinylcomonomer, if copolymers are desired, is dissolved in a suitable dipolaraprotic solvent and added over a period ranging from a few seconds up to1 hour at a temperature ranging from room temperature to about 200 C. toa stirred solution of an anhydrous lower-valence transition metal saltin an anhydrous dipolar aprotic solvent such as N,N-dimethylacetamide,also at a temperature from room temperature to about 200 C., and under asubstantially oxygen-free inert atmosphere such as N The reaction iscontinued for a period of about 1 to 24 hours with stirring at atemperature ranging from room temperature to about 200 C. After thereaction is completed the reaction mixture may be diluted with moredipolar aprotic solvent or with water to promote filtration, and thepolymer present in removed by filtration, Washed free of metal saltswith more dipolar aprotic solvent or with water, extracted with asolvent for unreacted halogen-containing aromatic compound, by-prod uctsand low-polymers, and finally dried.

For the industrial application of the process of this invention, thespent chromium liquor, which is in its higher valence state (CrCl as aresult of the coupling-polymerization reaction, and which containschlorine values from the halogen-containing aromatic compound undergoingthe coupling reaction, is reprocessed. When this is done, use of wateris avoided and only fresh dipolar aprotic solvent is employed to washthe polymer. Further, the halide salt of the transition metal is usedwhich corresponds to the halogen-containing aromatic compound couplede.g., chromous chloride is used with chlorine-containing aromaticcompounds losing chlorine in the complexing reaction. The dipolaraprotic solvent solutions of the transition metal in its higher valencestate (CrCl are evaporated to obtain the dry transition metal salt andthe recoverable dipolar aprotic solvent, which is recycled. The drytransition metal halide salt in its higher valence state, here CrCl isagain reduced with hydrogen at an elevated temperature and the lowervalence metal salt CrCl is obtained together with the correspondinghydrogen halide, both of which are recycled.

The recycle of chlorine values as HCl may be accomplished in two generalways. The recycled HCl may be fed directly to a chloromethylationreaction known to the art, such as the chloromethylation of1,4-dimethoxybenzene, where in the presence of excess HCl andformaldehyde the following reaction takes place:

21 101 201120 omo-oom CHzCl CHQO -OCH3 21120 CH CI In other instances itis preferred to utilize the recycled HCl by burning it with air oroxygen to elemental chlorine and water in a Deacon Process type ofoperation. The chlorine thus obtained is then used to convertalkylaromatic compounds to bis-(m-chloroalkyl) aromatic compounds, forexample p-xylene to u,a-dichloro-p-xylene, which can then be coupled topoly(p-Xylylene) in this process of this invention.

The invention will be more fully understood by reference to thefollowing illustrative embodiments.

EXAMPLE I.CONVERSION OF a,a'-DICHLORO-p- XYLENE TO POLY(p XYLYLENE)[POLY(p PHENYLENEDIMETHYLENE) 7 Part A.Preparation of a-0.9 N solutionof anhydrous CrCl in N,N dimelhylacetamide The preparation of solutionsof anhydrous CrCl in N,N dimethylacetamide was carried out essentiallyas described by C. E. Castro (J. Am. Chem. Soc., 83, 3262 (1961) for thepreparation of aqueous CrSO, solutions by the zinc-reduction of Cr (SOhydrate in water. In a typical preparation, 39.5 g. (0.25 mole) ofanhydrous CrCl was stirred under a nitrogen atmosphere in 270 ml. of N,Ndimethylacetarnide (redistilled from P under N and stored under N B.P.165-6" C.). To the lilac suspension was rapidly added 16.3 g. (g-atom)of 20 mesh granules of metallic zinc. Reaction commenced almost at once,accompanied by a temperature increase to about 80 C. and the developmentof a purple color in the solvent. After about one-half hour the purplecolor had changed to blue-green and the temperature had fallen to 55 C.Heat was applied and stirring was continued, with the temperature beingmaintained at 50-55 C. until the total elapsed time amounted to 2 hours.After cooling, the blue-green solution was pressure-filtered undernitrogen through a coarse-porosity sintered glass frit to removeunreacted zinc. The filtered solution was stored under nitrogen in aflask from which it could be withdrawn by hypodermic syringe. Samples of1-2 ml. size were withdrawn each day before use and reacted undernitrogen with excess (20 ml.) of 0.25 M aqueous FeCl solution; theferrous iron formed was immediately titrated with standard cericammonium sulfate solution to the green ferric phenanthroline end point;N=0.93. Such solutions showed only minor decreases in strength overperiods of several weeks. Contact with air gave an immediate colorchange from blue-green to brown.

'Part B.-Preparation of solutions of CrCl in other aprotic solventsEXTENT OF REDUCTION OF Cl'Clg BY Zn IN VARIOUS APROTIC SOLVENTS [16hrs., room temperature] Percent Reduction to Gr(Il) Appearance ofAprotic Solvent Supernatant Dimethyl sulf oxide N,N-dimethylacetamide.Acetone N,N-dimethylform amide Acetonitrile Light blue-green. Light blueBright 1t. green. Dark green Deep purple 25. 0

Alternatively, the presence of zinc chloride in the Cr(II) solutions maybe avoided if CrCl is reduced in solution with metallic Cr or if theCrCl is prepared by hydrogenreduction of anhydrous CrCl and thendissolved in the solvent to be used.

Part C.-Conversion of u,u dichloro p xylene to polyp xylylene) [poly (pphenylenedimethylene)] The coupling-polymerization reaction was carriedout in a -1111. three-necked round-bottom glass reaction flask which wasequipped with a pressure-equalizing addition funnel, a reflux-condenser,a thermometer and a magnetic stirrer. Both the flask and the funnel werewrapped with heating tape, and the funnel was also provided with athermometer. The entire system was well-flushed with nitrogen before useand nitrogen was supplied to the top of the reflux condenser at a smallpositive pressure /2 in. of Nujol).

To the reaction flask, against a current of nitrogen, was added, byhypodermic syringe, 25 ml. of a 0.913 N N,N- dimethylacetamide solutionof CrCl (22.8 millimoles). Into the addition funnel was introduced 1.33g. (7.6 millimoles) of oc,oc' dichloro p xylene (recrystallized fromacetone-hexane before use, M.P. 98-100 C.) and 20 ml. of redistilled N,Ndimethylacetamide. Heat was then applied to both the reaction flask andthe funnel. Nitrogen gas was slowly bubbled through the contents of thefunnel for 10-20 min. to remove oxygen and to provide agitation duringdissolution of the ot,oc' dichloro p Xylene. After about 25 min., whenthe temperature of the CrCl solution had been stabilized at 70:1" C.,and the temperature of the oc,ec' dichloro p xylene solution in thefunnel had also reached 70 C., the latter solution was allowed to flowas rapidly as possible into the former, with maximum stirring.Immediately the blue-green CrCl solution in the flask turned to deeppurple and solid began to separate. Within 3 minutes, with constant heatinput to the reactor flask, the temperature of the reactants rose to 82C. and then began to fall. The funnel was rinsed with 5 ml. additionalredistilled N,N dimethylacetamide and the rinse solution was immediatelyadded to the reactants. The reactor was thereupon cooled by the externalapplication of a stream of compressed air or nitrogen until thetemperature reached 70" C. The reactants were then maintained at 70i1 C.for a total reaction time of 2 hours, with continued stirring. At theend of the 2 hr. period the contents of the flask were poured into 500ml. of water. The solid present was collected, Washed well with waterand dried in vacuum at 35 C. A total of 0.79

g. (100%) of crude poly(p xylylene) was obtained as a light greenpowder. The crude material was extracted with acetone for 8 hrs. in aSoxhlet apparatus. Most of the green color was removed and 83.5% of theoriginal solid, after drying in vacuo, remained as acetone-insolublepoly- (p xylylene). The infrared absorption spectrum obtained with theacetone-insoluble polymer was essentially identical with a publishedspectrum for known poly(p xylylene) (R. A. Nyquist, Infrared Spectra ofPlastics and Resins, The Dow Chemical Co., Midland, Mich., 2nd ed., May3, 1961, Spectrum No. 124). The X-ray diffraction pattern of the polymershowed lines at 5.33 (very strong), 3.90 (very strong), and 2.79 A.(weak), as well as very weak lines at 3.50, 3.03, 2.70, and 2.30 A.(using Ni-filtered Cu radiation at 45 kilovolts, 15 milliamperes;Kr-filled Geiger tube operating at 1320 volts used as detector). Thecrystalline portion of the polymer is therefore the a-form of poly(pxylylene), and there is no detectable amount of the B-form present,which has a single spacing at 4.4 A. (C. H. Brown and A. C. Farthing, J.Chem. Soc., 3270 (1953); L. A. Errede and R. S Gregorian, J. PolymerSci., '60, 21 (1962) The polymer was completely soluble in benzylbenzoate within 4 min. at 305 C. and exhibited an inherent viscosity of0.095 (determined by the method described by T. E. Young, US. Patent2,999,820, Sept. 12, 1961, and by J. R. Schaefgen, J. Polymer Sci., 41,133 (1959)). The polymer began to soften without entirely melting at238-245 C. on a modified Dennis bar similar to the one described in theliterature (W. R. Sorenson and T. W. Campbell, Preparative Methods ofPolymer Chemistry, Interscience Publishers, Inc., New York, N.Y., 1961,p. 49). At a temperature of 412 C. specimens melt at once to a clearbrown melt, when placed on the Dennis bar.

9 EXAMPLE II.-CONVERSION OF 2,5 bis (CHLO- ROMETHYL) p XYLENE TOPOLY(2,5 DI- METHYL p =PHENYLENEDIMETHYLENE) In an apparatus and in amanner essentially similar to that described in Example I, 1.54 g. (7.6millimoles) of 2,5 bis (chloromethyl) p xylene (prepared by the methodof J. H. Wood, M. A. Perry and C. C. Tung, J. Am. Chem. Soc., 72, 2989),M.P. 132132.5 C.), was dissolved in 25 ml. of redistilled N,Ndimethylacetamide and rapidly added to 25 ml. of a 0.91 N N,Ndimethylacetamide solution of CrCl (22.8 millimoles). After 2 hrs. at 70C., a total of 1.00 g. (100%) of crude poly- (2,5 dimethyl pphenylenedimethylene) was obtained which, after 8 hrs. extraction withacetone in a Soxhlet apparatus and drying in vacuo, afforded an 81%yield of acetone-insoluble high polymeric poly(2,5 dimethylpphenylenedimethylene) as a white powder. This polymer was insolubleafter heating 30 min. in benzyl benzoate under nitrogen at 305 C. butwas completely soluble in Arochlor 1254 (a mixture of chlorinatedbiphenyls) after 10 minutes at 305 C., and exhibited an inherentviscosity of 0.33 (0.41 g. per 100 ml. of solvent) determined asdescribed in Example I. The X-ray dilfraction pattern of the polymershowed lines at 5.95 (s), 4.98 (m), 3.77 (s) and' 3.35 A. (w), as wellas very weak lines at 4.32, 2.63, and 2.15 A. The polymer melted sharplyat 336338 C. to a colorless melt on a Dennis bar. The infraredabsorption spectrum of the polymer contained a strong band at 880 cm?attributable to isolated aromatic ring hydrogen atoms.

EXAMPLE III.CONVERSION OF bis (CHLORO- METHYL)DURENE TO POLY(2,3,5,6TETRA- METHYL p PHENYL'ENEDIMETHYLENE) In an apparatus and in a manneressentially the same as that described in Example I, 1.76 g. (7.6millimoles) of his (chloromethyl)durene (prepared by the method of M. I.Rhoad and P. J. Flory, J. Am. Chem. Soc., 72, 2216 (1950), M.P.195-l96.5 C.) was dissolved in 25 ml. =redistilled N,N dimethylacetamideand added rapidly to 25 ml. of a 0.91 N N,N dimethylacetamide solutionof CrCl (22.8 millimoles). After 2 hrs. at 70 C., a total of 1.24 g.(102% yield) of crude poly(2,3,5,6 tetramethyl p phenylenedimethylene)was obtained, which yielded 1.13 g. (96%) of white, acetone insolublehigh polymer. This polymer was insoluble after heating 30 minutes inbenzyl benzoate at 305 C., or 40,minutes in boiling Arochlor 1254 (365390 C.). The X-ray diffraction pattern showed lines at 6.06 (m, broad),5.60 (vw), 4.13 (w), 3.28 (vw) and 2.71 A. (vw). The polymer melts withrapid blackening and decomposition on a Dennis bar at 500 C.

EXAMPLE IVCONVERSION OF 1,4 bis 0.-

CHLOROISOPROPYDBENZENE TO POLY(tx,u,a', a TETRAMETHYL p PHENYLENEDIMETH-YLENE) 1,4 bis (oz chloroisopropyl)benzene was prepared from 'diethylterephthalate by the method of Yu. V. Mitin (Zhur. Obshchei Khim., 28,3302 (1958)).

In an apparatus and in a manner essentially similar to that described inExample I, 2.28 g. (9.9 millimoles) of 1,4 bis (achloroisopropyl)benzene (M.P. 67.5- 71.5 C. corr.) was dissolved at roomtemperature in 36 ml. redistilled N,N dimethylacetamide and addedrapidly to 36.6 ml. of a 0.82 N N,N dimethylacetamide solution of CrCl(30 millimoles). After 2 hrs. at 2835 C., a total of 1.58 g. (99.5%) ofcrude ply(a,o,cz',oz'- tetramethyl p phenylenedimethylene) was obtained,which after extraction with acetone for 8 hrs. in a Soxhlet apparatus,and drying in vacuo, afforded a 93.5% yield of acetone-insoluble highpolymeric pOly(a,oc,a',oL' tetramethyl p phenylenedimethylene) as awhite powder.

Analysis.Calculated for (C H C, 89.94%; H, 10.07%. Found: C, 87.40%; H,9.78%.

The high polymer was insoluble after 30 min. in benzyl benzoate at 305C. but dissolved rapidly in boiling Arochlor 1254 (B.P. 365390 C.). InArochlor 1254 at 328 C it had an inherent viscosity of 0.086 (0.38 g.per 100 ml. solvent), determined as in Example I. When particles of thepolymer are placed on a Dennis bar at temperatures between 375 385 C.they volatilize almost completely at once to form a white fog. Thevolatilization is accompanied by some discoloration of the polymer. Attemperatures as low as 320 C. volatilization also occurs but appreciablepolymer remains behind and darkens. The X-ray scattering pattern showedlines as follows: 5.88 (vs), 5.12 (s), 3.26 (w) and 2.13 A. (vw).

A sample of the polymer was placed in a vacuum sublimation apparatuswhich was then evacuated and strongly heated with a Bunsen burner.Decomposition of the polymer specimen was again observed and at the sametime a white solid began to collect on the cold finger collector of thesublimation apparatus. This white solid was insoluble in acetone and inturn exhibited the same decomposition behavior at 375-385 C. on theDennis bar as did the original polymer. This result may be interpretedas evidence that the poly(a,u,u',a-tetramethyl-pxylylene) obtained inthis example decomposes at 375- 385 C. to form monomerica,a,a',a'-tetramethylquinodimethane, Which is stable in the gas phase,and passes through the vacuum of the sublimation apparatus to the coldfinger collector where it condenses and immediately repolymerizes topoly(a,u,a',u'-tetramethyl-p-xylylene).

EXAMPLE V.-'CONVERSION OF a,u'-DIBROMO-O XYLENE TOPOLY(o-PHENYLENEDIMETHYL- ENE) [POLY(o-XYLENE)] In an apparatus and in amanner essentially similar to that described in Example I, 2.11 g. (8millimoles) of Ot,0t'-dlb1OITlO-O-Xyl6Ile (recrystallized from n-hexanebefore use, M.P. -96 C.) was dissolved in 25 ml. redistilledN,N-dimethylacetamide and rapidly added to 21 ml. of a 0.95 NN,N-dimethylacetamide solution of CrCl (2O millimoles). After 2 hrs. at70 C. a total of 0.3 g. of a dark brown crude polymer was obtained.Dissolution of the crude polymer in hot toluene, followed byprecipitation in methanol and drying in vacuo yielded 0.2 g. (24%) ofpurified solid poly(o-phenylenediamethylene) softening at 93 97 C. to aviscous melt on a hot stage microscope. Poly(o-xylylene) has beenreported to melt at -110 C. by L. A. Errede, J. Polymer Sci., 49, 253(1961).

EXAMPLE VI.CONVERSION OF 4,5 -BIS CHLORO- METHL) -o-XYLENE TO POLY(4,5-DIMETHYL-o- PHENYLENEDIMETHYLENE) The preparation of4,5-bis(chloromethyl)-o-xylene was carried out according to thedirections of J. von Braun and I. Nelles, Ber., 67, 1094 (1934) exceptthat twice as much formaldehyde solution was used and the reaction timewas extended to 27 hrs., M.P. 103104 C.; Von Braun and Nelles reported aM.P. of 105 106 C.

In an apparatus and in a manner similar to that described in Example I,1.54 g. (7.6 millimoles) of 4,5- bis-(chloromethyl)-o-xylene wasdissolved in 25 m1. redistilled N,N-dimethylacetamide solution andrapidly added to 25 ml. of a 0.91 N N,N-dimethylacetamide solution ofCrCl (22.8 millimoles). After 2 hrs. at 70 C., a total of 1.00 g. ofcrude poly(4,5dimethyl-ophenylenedimethylene) was obtained, whichyielded 0.742 g. (74.2%) of acetone-insoluble high polymericpoly(4,5-dimethyl-o-phenylenedimethylene) as a white powder.

Analysis.-Calculated for (C H C, 90.85%; H, 9.15%. Found: C, 90.91%; H,9.09%.

The polymer dissolved completely within 2 min. in benzyl benzoate, at305 C., and exhibited an inherent viscosity of 0.095 (0.39 g. per 100ml. solvent) determined as described in Example I. The X-ray scatteringpattern showed lines as follows: 11.63 (m), 5.83 (m), 4.46 (w),

. 4.15 (vw), 3.83 (m), and 3.17, 2.80 and 2.58 A. (vw).

The polymer melted sharply at 300 C. to a colorless melt when placed ona Dennis bar at 300 C.

EXAMPLE VII. CONVERSION OF 5,6-BIS-(CI-ILO- ROME'IHYI.)INDANE TOPOLY(5,6-INDANYL- ENEDIMETHYLENE) Part A 1st fraction, 43.6 g., B.P.140-152 c. (Ll-1.5 mm. Hg) 2nd fraction, 219.6 g., B.P. l55165 C. (09-13mm. Hg) 3rd fraction, 73.7 g., B.P. l60-l77 C. (OB-1.5 mm. Hg)

From the second fraction, by recrystallization from petroleum ether,there was isolated 93.7 g. (14.7%) of solid, M.P. 5l69 C. Repeatedrecrystallization from acetone and then ethanol yielded 34.3 g. of whiteneedles, M.P. 7374.5 C. Several further recrystallizations from ethanolgave an analytical sample, MI. 74.5 -75.5 C.,

corr.

Analysis.'-Calculated for C11H12Cl2i C, 61.41%; H, 5.63%; C1, 32.96%.Found: C, 61.25%; H, 5.58%; Cl, 33.13%.

The assignment of the 5,6-bis-(chloromethyl)indane structure to thecompound is based on the above analysis and on its nuclear magneticresonance and infrared spectra. The NMR spectrum showed a singlet peakfor two equivalent aromatic ring protons, at a tan value of 3.1,consistent only with a 5,6- or a 4,7-bis-(chloromethyl)- indanestructure, eliminating the possible 4,5- and 4,6 bis-(chloromethyDindanestructures. The infrared spectrum showed a medium intensity band at 884cmr associated with isolated ring hydrogen atoms, which is consistentonly with the assigned 5,6-bis-(chloromethvijindane structure.

Part B.Preparalin of poly (5,6-indanylenedimethylene) 1. POLYMERIZATIONA'l cfli C. USING 50% EXCESS In an apparatus and in a manner essentiallysimilar to that described in Example I, 1.68 g. (7.83 millimoles) of5,6-bis-(chloromethyl)indane was dissolved in redistilledN,N-dimethylacetamide and rapidly added to 25 ml. of a 0.94 NN,N-dimethylacetamide solution of CrCl (23.5 millimoles). After 2 hrs.at 70 C., a total of 1.10 g. (97.4%) of crudepoly(5,6-indanylenedimethylene) was obtained as a friable white solid,which afforded a 76.5% yield of white insoluble high polymer after 6hrs. extraction with acetone in Soxhlet apparatus.

Analysis.Calculated for (C H C, 91.61%; H, 8.39%. Found: C, 90.00%; H,8.21%.

The infrared spectrum obtained with the high polymer contained a band at872 cm. for isolated aromatic ring hydrogens. The polymer was swelled bybenzyl benzoate at 205 C. and dissolved completely within min. in thatsolvent at 305 C. At 305 C. and a concentration of 0.39 g. per 100 ml.benzyl benzoate it exhibited an inherent viscosity of 0.11, determinedas in Example I. The X-ray scattering diagram showed lines at 12.45 (w),8.85 (vw), 6.15 (w), 5.87 (vw), 5.40 (vw), 4.55 (vw), 3.92 (vw), 3.80(vw), 2.93 (vw), 2.84 (vw) and 2.73 A. (vw). The polymer melted sharplyto a colorless melt which slowly turned brown when placed on a Dennisbar at 302 C.

1.2. 2. POLYMERIZATION AT 07%; C. USING 100% EXCESS 1 2 In an apparatusand in a manner essentially similar to that described in Example I, 1.72g. (8 millimoles) of 5,6-bis-(chloromethyl)indane was dissolved in 25ml. redistilled N,N- dimethylacetamide and added rapidly to 35 ml. of a0.925 N N,N-dimethylacetamide solution of CrCl (32 millimoles). After 2hrs. at 70 C. there was obtained a crude poly(5,6-indanylenedimethylene)which, after washing well with water, was immediately transferred to aSoxhlet extractor and extracted 4 hrs. with acetone and finally dried. Atotal of 0.75 g. (65.2%) of acetoneinsoluble high polymer was obtainedas a white powder. This polymer melted at 305312 C. on a Dennis bar. Ithad an inherent viscosity of 0.05 in benzyl benzoate at 305 C. (0.39 g.per 100 ml. solvent), determined as described in Example I.

Analysis.-Calculated for (C H C, 91.61%; H, 8.39%. Found: C, 90.85%; H,8.30%.

EXAMPLE VIII.--CONVERSION OF 1,4-DIBROMO- 1,2,3,4-TETRAHYDRONAPHTHALENETO POLY 1,4- 1,2,3,4-TETRAHYDRO NAPHTHYLENE) In an apparatus and in amanner essentially similar to that described in Example I, 2.3 g. (8millimoles) of freshly-recrystallized1,4-dibromo-1,2,3,4-tetrahydronaphthalene (hexane M.P. 92-93" C.)prepared by the method of A. G. Anderson, Jr., and R. E. Anderson, J.Org. Chem., 22, 1197 (1957) was dissolved in 30 ml. redistilledN,N-dimethylacetamide and rapidly added to 25 ml.

of a 0.948 N N,N-dimethylacetamide solution of CrCl (23.7 millimoles).After 2 hrs. at 70 C. a total of 0.94 g. (90.4%) of crude polymer wasobtained, which afforded a 77.5% yield of white, insoluble high polymerafter 4 hrs. extraction with acetone in a Soxhlet apparatus.

Analysis.--Calculated for (C H C, 92.26%; H, 7.74%. Found: C, 91.29%; H,7.87%; Br, 0.45%.

The polymer melted at 205215 C. with browning to a viscous melt on a hotstage microscope. The X-ray diffraction pattern showed three broad linesat 6.47 (m), 4.11 (vw) and 2.13 A. (vw). The polymer dissolvedcompletely in benzyl benzoate within 3 min. at 222 C.; it exhibited aninherent viscosity at 222 C. in benzyl benzoate of 0.25 (0.42 g. per 100ml. solvent), determined as in Example I.

EXAMPLE IX.CONVERSION OF x,a-DIBROMO-m- XYLENE TOPOLY(rn-PHENYLENEDIMETHYL- ENE) POLY(rn-(YLYLENE) In an apparatus and ina manner essentially similar to that described in Example I, 2.01 g.(7.6 millimoles) of a,a-dibromo-m-xylene (and recrystallized fromn-hexane before use M.P. 76.2-76.8 C.) was dissolved in 25 ml. ofredistilled N,N-dimethylacetamide and rapidly added to 25 ml. of a 0.912N N,N-dimethylacetamide solution of CrCl (22.8 millimoles). After 2 hrs.at 70 C., a total of 0.663 g. (84%) of crude polymer was obtained, whichyielded 0.252 g. (38%) of off-white acetone-insoluble high polymer. Thepolymer was completely soluble in benzyl benzoate at room temperature.It melted at 97- 98 C. on a hot stage microscope melting point apparatusto a viscous melt.

EXAMPLE X.-CONVERSION OF 4,6-BIS- (CHLORO- METHYL) -m-XYLENE TOPOLY(4,6-DIMETHYL- m-PHENYLENEDIMETHYL'ENE) Part A.P0-lymerizati0n at 70C. using 45% excess CrCl In an apparatus and in a manner essentiallysimilar to that described in Example I, 1.34 g. (6.8 millimoles) of4,5-bis-(chloromethyl)-m-xylene (recrystallized from nhexane before use,M.P. 96 C.) was dissolved in 22.5 ml. redistilled N,N-dimethylacetamideand rapidly added to 22 ml. of a 0.90 N N,N-dimethylacetamide solutionof CrCl (19.8 millimoles). After 2 hrs. at 70 C. a. total of 0.852 g.(93.5%) crude poly(4,6-dimethyl-m-xylylene) was obtained which affordeda 70% yield of acetoneinsoluble high polymer melting at 135-l3-8 C. to aviscous liquid on a hot stage microscope melting point apparatus. Thepolymer was completely soluble in benzyl benzoate at room temperature.The X-ray scattering diagram showed lines at 8.68 (vs), 7.90 (m), 4.98(m), 4.25 (w), 3.89 (m), 3.48 (m), 3.32. (W) and 2.88 A. (vw). Thepolymer dissolved within 1 min. in benzyl benzoat-e at 222 C. but asmall amount of gel prevented the determination of a reliable inherentviscosity.

Part B.Effect of polymerization temperature and amount of excess CrCl onyield and inherent viscosity of poly(4,6-dimethyl-m-xylylene) 14 125 C.and rapidly added to 30.3 ml. of a 0.925 N N,N-dimethylacetamidesolution of CrCl (28 millimoles) at 125 C. After 2 hrs. at 125 C. thecrude poly(2,4,6 trimethyl-m-xylylene) was isolated, Washed with Waterand immediately placed in a Soxhlet extractor where it was extracted 6hrs. with acetone and then dried. A total of 1.005 g. ofacetone-insoluble p0ly(2,4,5-trimethyl-mxylylene) (98.5% yield) wasobtained as a white powder. This polymer Was insoluble after 30 min. inbenzyl benzoate at 222 C. but dissolved in 2 min. .at 305 C. and had aninherent viscosity of 0.04 (0.39 g. per 100 ml. solvent), determined asdescribed in Example I.

The polymer melted at 277 C. on a Dennis bar.

Analysis.Calculated for (C H 4) C, 90.35%; H, 9.65%. Found: C, 89.03%;H, 8.87%.

EXAMPLE XII.OONVERSION OF 5,8-BI'S-(CHLO- ROMETHYL)TETRALIN TO POLY[5,8(1,2,3, 4 TETRAHYDRO)NAPHTHYLENEDIMETHYL- ENE] In an apparatus and in amanner essentially similar to that described in Example I, 1.67 g. (7.3millimoles) of 5,8-bis-(chloromethyl)tetralin (prepared by the method ofG. M. Badger, J. W. Cook and G. W. Crosbie, J. Am.

25 Chem. Soc., 1432 (1947), M.P. l181l8.5 C.) was dis- CrCh SolutionExtracted Run Amount Taken Reaction Yield, Ninh 2 Appearance No. N Temp,0. percent 1 Ml. mM Percent excess 1 0. 925 30.3 28 100 26 trace Darksolid. 2 0. 925 30.3 28 100 70 78. 8 0.055 White powder. 3 0.925 30. 328 100 125-3 81.0 0.20 Granules and sheets faintly green.

1 After 6 hrs. extraction with acetone in a Soxhlet apparatus. 2 0.42 g.per 100 ml. benzyl beuzoate.

EXAMPLE XI.-CONVERSION OF BIS-(CHLORO- METHYL)MESITYLENE TO POLY(2,4,6TRI- METHYL-m-XYLYLENE) Part A.P0lymerization at 70 C. using 44% excessCrCl Part B.P0lymerizatiow at 125 C. using 100% excess CrCl In anapparatus and in a manner essentially similar to that described inExample I, 1.52 (7 millimoles) of bis- (chloromethyl)mesitylene (thematerial used in Part A, above, was recrystallized from ethanol usingDarco B Carbon to decolorize, M.P. 103106 C.) was dissolved in 25 ml.redistilled N,N-dimethylacetamide heated to solved in 25 ml.re-distilled N,N-dimethylacetamide and rapidly added to 25 ml. of a 0.87N N,N-dimethylacet-amide solution of CrCl (22 millimoles). After 2 hrs.at 70 C. a total of 1.13 g. (98%) of a crumbly, faintly green solid wasobtained, which afforded, after 5% hrs. extraction was acetone in aSoxhlet apparatus and drying in vacuo, an 86.6% yield of off-white,acetone-insoluble high polymer as a crumbly solid.

Analysis.Calculated for (C H C, 91.08%; H, 8.92%. Found: C, 90.94%; H,8.85%.

The X-ray diffraction pattern showed lines as follows: 7.77 (W), 6.97(vW), 6.47 (vw), 5.94 (w), 5.40 (W), 4.39 (m), 3.86 (w) and 3.72 A. (W).The polymer dissolved within 3 min. in Arochler 1254 at 328 C. and hadan inherent viscosity of 0.25 (0.39 g. per 100 ml. solvent), determinedas in Example I. It melted sharply to a clear brown melt when placed ona Dennis bar at 345 343 C.

EXAMPLE XIII.CONVERSION OF 1,4-BIS-(CHLO- ROMETHYL) NAPHTHALENE TOPOLY(1,4- NAPHTHALENEDIMETHYLENE) In an apparatus and in a manneressentially similar to that described in Example I, there was obtainedfrom 15 reacting 1.69 g. (7.5 millirnoles) of1,4-bis-(chloromethyl)naphthalene (prepared by the method of G.M.Badger, I. W. Cook and C. W. Crosbie, J. Chem. Soc., 1432 (1947), M.P.146147.5 C.) in 25 ml. redistilled N,N- dimethylacetamide with 25 ml. ofa 0.90 N N ,N-dirnethylacetarnide solution of CrCl (22.5 millirnoles),after 2 hrs. at 70 C., a total of 1.18 (102%) of crude poly-(1,4-naphthylenedimethylene') as a brittle, faintly green solid, whichafter extraction 5% hrs. with acetone in a Soxhlet apparatus, followedby drying in vacuo, afforded in 80% yield of acetone-insoluble highpolymeric poly (1,4-naphthylenedimethylene) as a friable white solid.The high polymer dissolved completely in 8 min. in Arochlor 1254 at 305C. but was only partly soluble in benzyl benzoate after 25 min. at thistemperature. The high polymer had an inherent viscosity of 0.21 (0.40 g.per 100 ml. solvent) in Arochlor 1254 at 305 C. determined as in ExampleI. On the Dennis bar it melted sharply at 335-338 C. to a colorless meltwhich rapidly turned brown. The X-ray difiraction pattern showed linesas follows: 6.82 (w), 5.81 (w), 5.11 (w), 4.67 (vw), 3.93 (s), 3.41 (vw,broad).

EXAMPLE XIV.--CONVERSION OF oc,a',2,3,5,6-HEX ACHLORO-p-XYLENE TOPOLY(2,3,5,6-TETRA- CHOLORO-P-PHENYLENEDIMETHYLENE) In an apparatus andin a manner essentially similar to that described in Example I, 2.38 g.(7.6 millimoles) of u,a', 2,3,5,6-hexachloro-p-xylene (recrystallizedfrom benzenehexane, M.P. 181-181.5 C., corr.) was dissolved in 25 ml. ofredistilled N,N-dimethylacetamide and rapidly added to 25 ml. of a 0.912N N,N-dimethylacetamide solution of CrCl (22.8 millimoles). After 2 hrs.at 70 C. a total of 1.58 g. (101%) of crudepoly(2,3,5,6-tetrachloro-p-phenylenedirnethylene), was obtained, whichafter 8 hrs. extraction with acetone in a Soxhlet apparatus and dryingin vacuo, afforded a 93.5% yield of acetone-insolublepoly(2,3,5,6-tetrachloro-p-phenylenedimethylene) as a white powder.

Analysis-Calculated for (C H Cl C, 39.70%; H, 1.67%; C1, 58.61%. Found:C, 39.46%; H, 1.57%; Cl, 58.82%.

' The high polymer was insoluble in benzyl benzoate and Arochlor 1254 at305 C. and also insoluble in boiling Arochlor 1254 (B.P. 365-390 C.).The X-ray diffraction pattern showed a series of very weak bands at 8.04(broad, 4.25, 3.92, 3.68, 3.29, 3.21, 2.84, 2.70, 2.47 and 2.10 A. Onthe Dennis bar the high polymer turned brown with out melting at 525 C.

7 EXAMPLE XV.CONVERSION OF 4,4'-BIS-(CHLO ROMETHYL) DIPHENYL ETHER TOPOLY[P=P OXIDODI (PHENYLMETHYLENE) Part A.-P0lymerizati0n at 70 C. using50% excess Cr C12 I total of 1.46 g. (99.3%) of crudepoly(p,p'-oxidodi(phenyhnethylene) was obtained as a pale green powder,which after extraction for 7% hrs. with acetone in a Soxhlet .apparatus,and drying in vacuum, afforded a 73.5% yield of acetone-insoluble highpolymeric poly[p,p-oxidodi (phenylmethylene)] as a pale green powder.The high polymer softened at 185-190" C. on a hot stage microscope .to aviscous melt. The polymer gave an X-ray scattering pattern with lines at5.54 (w), 4.62 (vs), 4.30 (vw), 4.15 (s), 3.23 (w) and 2.84 A. (vw).

The high polymer was partly soluble in'benzyl benzoate at roomtemperature and completely soluble at 138 C. It had an inherentviscosity of 0.09 in benzyl benzoate at 222 C. (0.42 g. per m1.solvent), determined as described in Example I.

Part B.--POZymerizati0n at C. using 100% excess CICZZ In an apparatusand in a manner similar to that described in Example I, 1.87 g. (7millirnoles) of 4,4'-bis- (chloromethyl)-diphenyl ether in 25 ml.redistilled N,N- dimethylacetamide at 125 C. was added rapidly to 30.3ml. of a 0.925 N N,N-dimethylacetamide solution of CrCl (28 millinioles)also at 125 C. After 2 hrs. at 123-128 C. the crudepoly[p,p-oxidodi(phenylrnethylene)] was isolated and washed well withWater. It was immediately transferred to a Soxhlet extractor, extracted6 hrs. with acetone and finally dried. A total of 1.37 g. (90% yield) ofacetone-insoluble high polymer was obtained as a pale green solid,containing some hard granules. The polymer melted at 186 C. on a Dennisbar. It was not soluble in benzyl benzoate after 30 min. at both 222 and305 C.

EXAMPLE XVI.-CONVERSION OF 2,5-BlS-(CHLO- ROMETHYL) 1,4 DIMETHOXYBENZENETO POLY(2,5 DIMETHOXY p PHENYLENEDI- METHYLENE) In an apparatus and in amanner essentially similar to that described in Example I, 1.7 g. (7.2millimoles) of 2,5-bis-(chloromethyl)-l,4-dimethoxybenzene (prepared bythe method of Brunner, U.S. Patent 1,887,396, 1933, as modified by J. H.Wood and R. E. Gibson, J. Am. Chem. 500., 71, 393 (1949); M.P. -165.5C.) was dissolved in 25 ml. of redistilled N,N-dimethylacetamide andadded rapidly to 25 ml. of an 0.86 N N,N-dimethylacetamide solution ofCrC1 (21.6 millimoles). After 2 hrs. at 70 C., a total of 1.0 7 g. (90%)of crude poly (2,5-dimethoxy-p-phenylenedimethylene) was obtained as awhite powder which, after 6%. hrs. extraction with acetone in a Soxhletapparatus and drying in vacuum alforded a 82.5% yield ofacetone-insoluble high polymericpoly(2,5-dimethoxy-p-phenylenedimethylene) as a white powder at 233-237C. in a hot stage microscope to a viscous melt. The high polymerreported here was completely soluble in benzyl benzoate at 205 C., butnot at 138 C. In benzyl benzoate at 222 C. it dissolved completely in 3min., and exhibited an inherent viscosity of 0.47 (0.42 g. per 100 ml.solvent) determined as described in Example I.

The X-ray diifraction pattern for the high polymer showed lines asfollows: 5.83 (m), 4.87 (vw), 4.33 (w), 3.92 (s), 3.47 (w), 3.18 (vw),2.68 (vw), 2.33 A. (vw).

A series of similar polymerization runs were carried out essentially asdescribed above except that the polymerization conditions were varied(time, temperature and ratio of CrCl to dihalide). The experiments aresummarized in Table I.

It is evident from the table that the higher yields and higher molecularweights are obtained at room temperature rather than at 70 C. and thatuse of CrCl at a 100% excess rather than a 25% excess, based on 1 moleof CrCl per atom of chlorine in the bis-(halomethyl) aromatic compound,provides higher molecular weight and higher yield.

TABLE I.EFFEOT OF REACTION TIME,- TEMPERATURE AND AMOUNT OF CrClz ONCOUPLING OF 2,5-BIS-(CHLOROME'IHYL)-1,4-DIMETHOXYBENZENE IN DMAcSOLUTION TO POLY(2,5-DIMETHOXY-p-PHENYLENEDIMETHYLENE) Amount of2,5-bis-(chloromethyl)-1,4-dimethoxybenzene taken: 1.90 g. (8.1 mmoles)in 25 redistllled N,N-

dimethylacetamlde.

ClClzt prepared by Zn-reduction of anhydrous @013 in redistilledN,N-dimethylacetamide.

OrCh solution Reaction Conditions Polymer Yield, percent RunEta-inherent No. (extracted N Ml. ClClz, Temp, Time, Crude Extracted 1polymer mmoles 0. min.

I 1 Extracted 2 hrs. with acetone in a Soxhlet apparatus, until extractshowed no cloudiness on dilution with water.

2 Viscosity determined in benzyl benzoate (0.42 g. per 100 m1. solvent)at 222 C. as described in Example 1.

EXAMPLE XVII.CONVERSION OF 2,5-BIS-(CHLO- ROMETHYL) 1,4DI-n-BUTOXYBENZENE TO POLY(2,5 DI-n-BUTOXY p PHENYLENEDI- METHYLENE)Part A.-Synthesis 0 2,5-bis(chl0r0methyl)-],4-di-nbutoxybenzene Thiscompound was prepared by twice chloromethylating 1,4-di-n-butoxybenzeneaccording to the method described by J. H. Wood and R. E. Gibson, I. Am.Chem. Soc., 71, 393 (1949), for the bis-(chloromethylation) of1,4-dimethoxybenzene. The product obtained melted at 83.4 84.'5 C., ingood agreement with the melting point of 8l-2 C. reported by N. N.Melnikov and .M. V. Prilutskaya, Zhur. Obshchei Khim., 29, 3746 (1949)for this same compound prepared by another chloromethylation procedure.

Part B.Preparation of p0ly(2,5-di-n-butoxy-pphenylenedimethylene) In anapparatus and in a manner essentially similar to that described inExample I, 2.23 (7 millimoles) of 2,5-bis-(chloromethyl) 1,4di-n-butoxybenzene was dissolved in ml. of redistilledN,N-dimethylacetamide and rapidly added to 25 ml. of a 0.84 'NN,N-dimethylacetamide solution of CrCl (21 millimoles). After 2 hrs. at70 C., a total of 1.64 g. (92.5%) of crude poly (2,5-di-n-butoxypphenylenedimethylene) was obtained as a faintly-green solid which after6 /2 hrs. extraction with acetone in a Soxhlet apparatus and drying invacuo, afforded a 84.6% yield of acetone insoluble high polymericpoly(2,5 di-n-butoxy-p-phenylenedimethylene) as a white powder.

Analysis.Calculated for (C1 H240 2) C, H, 9.67%. Found: C, 77.35%; H,9.69%.

The high polymer was swelled by benzyl benzoate at 25 C. but did notentirely dissolve; it was completely soluble at 138 C. At 222 C. inbenzyl 'benzoate it exhibited an inherent viscosity of 0.19 (0.42 g. per100 ml. solvent), determined as described in Example I.

The high polymer melted sharply at 226 C. on a Dennis bar. Its X-raydifiraction pattern showed lines as follows: 13.10 (s), 6.32 (vw), 5.68(vw), 4.67 (vw), 4.35 (vw), 3.96 (m), 2.98 (vw), 2.72 (vw), 2.47 (vw),and 2.15 A. (vw).

EXAMPLE XVIII.-CGNVERSION OF 1,2,4,5-'I-ET- RAKIS(BROMOMETI-IYL)BENZENETO A POLY- -MERIC PRODUCT OF HIGH THERMAL STA- BILITY In an apparatusand in a manner essentially similar to that described in Example I, 3.20g. (7.1 millimoles) of 1,2,4,5 tetrakis(bromomethyl)benzene, M.P. 160-160.5 C. (prepared bya published method, Chem. Ber.,

89, 2328 (1956)) in 25 ml. of redistilled N,N dimethylacetamide wasrapidly added to 37.6 ml. of a, 0.948 N N,N dimethylacetamide of CrCl(35.6 millimoles). After 2 hrs. at 70 C. a total of 1.06 g. of crudepolymer was obtained which after extraction with acetone in a Soxhletapparatus yielded 0.72 g. of a light brown solid.

Analysis.-Found: C, 79.06%; H, 6.53%; Br, 14.51%.

Thermogravimetric analysis of this' polymer under nitrogen, at a heatingrate of 150 C./hour, showed a gradual weight loss started at 160 C.which reached 60% at 500 C. The final residue at 900 C. amounted to 56%of the weight of the starting polymer.

EXAMPLE XIX.CONVERSION OF 1,4-BIS- (egos-DI- CHLOROBENZYL )BENZENE TOPOLY aged-DI- PHENYL-p-XYLYLIDENE) In an apparatus and in a manneressentially similar to that described in Example I, 0.99 g. (2.5millimoles) of 1,4 bis (oc,oc dichlorobenzyl)benzene (prepared bytreating 1,4 dibenzoylbenzene with phosphorous pentachloride, M.P. -92C.) in 25 ml. redistilled N,N- dimethylactamide was added rapidly to20.3 ml. of a N, N-dimethylacetamide solution of CrCl (20 millimoles).After 2 hours at 70 C. a total of 0.52 g. (82.5%) of crude polymer wasobtained, which after Soxhlet extraction with acetone yielded 74% ofpoly(a,a-diphenyl-pxylylidene) as an orange powder.

Analysis.C, 93.84%; H, 5.54%; Cl, 0.30%.

This analysis corresponds well to the formula Thermogravimetric analysisof this polymer under nitrogen, at a heating rate of C./h0ur, showed noweight loss up to 450 C., a 7% weight loss at 500 C. and a residue of58% at 900 C.

The substance did not dissolve after 1 hour in Arochlor 1254 at 305 C.Swelling was observed.

EXAMPLE XX.CONVERSION OF 4,4'BIS-(oc,oz-DI CHLOROBENZYL)DIPHENYL ETHERTO POLY [4,4'-OXYB IS- oz-PHENYLB ENZYLIDENE) In an apparatus and .in amanner essentially similar to that described in Example I, 1.21 g. (2.5millimoles) of 4,4-bis-(a,a-dichlorobenzyl)diphenyl ether in 25 ml. ofredistilled N,N-dimethylacetamide was rapidly added to 20.3 ml. of a0.984 N N,N-dimethylacetamide solution of CrCl (20 millimoles). After 2hours at 70 C., a total of 0.98 g. 114% yield) ofcrude polymeric productwas obtained, which, after extraction in a Soxhlet apparatus withacetone aiiorded a 91.8% yield. ofpoly[4,4'-oxybis(a-phenylbenzylidene)] as a yellow solid.

Analysis.Calculated for (C gI-I O) Cl: C, 89.5%; H, 5.15%; Cl, 0.5%.Found: C, 89.66%; H, 5.24%; Cl, 0.49%.

Thermogravimetric analysis of this polymer under nitrogen, at a heatingrate of 150 C./hour, showed no weight loss up to 425 C., a loss of only5% at 500 C. and a final residue of 57.5% at 900 C.

The substance did not dissolve after 1 hour in Arochlor 1254 at 305 C.although swelling was observed.

EXAMPLE XXL-CONVERSION OF c,a,0z,oc',0t',ot' HEXACHLORO-p-XYLENE TO APOLYMERIC PRODUCT In an apparatus and in a manner essentially similar tothat described in Example I, 2.40 g. (7.65 millimoles) ofa,a,u,ot',a',a'-hexachloro-p-xylene, M.P. 1l2-ll3 C., in 17 ml. ofredistilled N,N-dimethylacetamide was rap- 7 idly added to 28 ml. of a0.82 N N,N-dimethylacetamide EXAMPLE XXII.FORMATION OF POLY[4,4'-

OXYBIS(oc-PHENYLBENZYLIDENE)] IN SITU IN A GLASS CLOTH SUPPORT A stripof glass cloth about 12 x 2 x inches in size is impregnated With asolution containing about 25% byweight of4,4'-bis(a,a-dichlorobenzyl)diphenyl ether in N,N-dimethylacetarnide forabout 5 min. at room temperature under an inert atmosphere (nitrogen) ina glove box. The strip is then removed from the impregnating bath andallowed to drain for 5 minutes. It is then rapidly immersed in a stirredbath containing a 1N solution of CrCl in N,N-dimethylacetarnide heatedto 70 C., and allowed to remain there for 15 minutes. During this-timethe yellow poly[4,4'-oxybis( x-phenylbenzylidene)] forms in theinterstices of the glass cloth and on the surface of the glass fibersthemselves.

The strip is then removed from the polymerization bath and carefullydipped in three successive de-ionized water baths to wash out all metalsalts and N,N-dimethylacetamide solvent. It is found that the strip nowhas a dense coating and filling of the polymeric poly[4,4-oxybis(u-phenylbenzylidene)] deposited in situ by the reactive couplingagent of this invention.

The coated and filled strip is finally subjected to heat and pressure(about 300-400 C. and 10,000 p.s.i.g.) whereupon a degree of fusion ofthe deposited polymer takes place rendering the strip relativelyimpervious to the passage of gases and liquids. Several such strips canbe laminated together by heat and pressure to afford structures of greatvalue as ablative heat barriers for shielding purposes in suchapplications as rocket nozzles, missiles and space vehicles.

While the above in situ deposition method is particularly suited forthose polymers prepared by the process of this invention which areusually obtained in the insoluble crosslinked form as a consequence ofthe use of monomers of functionality greater than two such as forexample, 4,4 bis (a,a-dichlorobenzyl)benzene or1,2,4,5-tetrakis(bromomethyl)benzene, it is equally Well suited to thedeposition of the soluble non-crosslinked poly(arylenedialkylidene)polymers prepared by the coupling of bis-(a-haloalkyDaromatic compounds.For example, poly(p-xylylene) can be deposited in situ in varioussubstrates by impregnating the substrate with a,a-dichloro-p-xylene andthen treating the impregnated object with the CrCl coupling solution,and finally washing out the metal salts with water. Fusion isaccomplished '20 at about 200-400 C. under pressure, and impervious,heat-resistant impregnated objects are obtained.

It is also feasible to impregnate the substrate first with the CrClcoupling solution, whereupon the CrCl coupling agent itself becomesabsorbed and otherwise held in the substrate. Subsequent contacting ofsubstrates thus impregnated with coupling agents with thehalogencontaining monomers disclosed above thencauses the rapiddeposition of the polymer in the substrate. However, it usually is moredifficult to wash out the metal salts and excess coupling agent fromsuch treated materials.

It is evident that the above-described polymer depo sition methods,because of the rapidity of the formation of polymer, are ideally suitedto a continuous operation in which the material to be impregnated, forexample, a continuous strip of glass cloth, is passed successivelythrough a monomer impregnation bath, a pair of opposed rollers to removeexcess impregnation solution, a coupling bath containing CrCl rollers toremove ex cess liquid, a wash bath, rollers to remove bulk Water, adrying chamber and finally heated opposed rollers where pressure isapplied and the impregnated material finally undergoes sufiicient fusionto firmly fix it in place in the substrate and provide an impervious,continuous impregnated strip.

EXAMPLE XXIIL-CONVERSION OF TEREPH- THALOYL DICHLORIDE TO A SOLUBLEPOLY- MERIC PRODUCT In an apparatus and in a manner essentially similarto that described in Example I, 1.53 g. (7.5 millimoles) ofterephthaloyl dichloride M.P. 8283 C., in 25 ml. of redistilledN,N-dimethylacetamide was rapidly added to 25 ml. of a 0.916 NN,N-dimethylacetamide solution of CrCl (23 millimoles) at 72 C. Anexotherm to 83 C. was observed and a brown solution was obtained. After2 hours at 70 C. it was found that 4.5 millimoles of CrCl had notreacted; for a consumption of 1.3 moles of CrCl per equivalent ofchlorine in the diacyl chloride. The reaction mixture was diluted with500 ml. H 0 and a green-brown fine gelatinous solid was recovered bycentrifugation. The solid was Washed with water and finally boiled with1:1 HCl solution for 10 min. A yellow solid separated and was collected,washed and dried, 0.633 g. (65% based on (CO.-C H -CO-}. The solidsoftened and became plastic with decomposition and darkening, at 230250C. on a Dennis bar.

Analysis.Calculated for {COC H CO-} C, 72.73%; H, 3.05%. Found: C,66.98%; H, 4.70%; residue, 3.2%.

The polymer Was completely soluble in N,N-dimethy1 acetamide and couldbe reprecipitated by adding such solutions to water. Reprecipitatedmaterial exhibited an inherent viscosity of 0.1 (0.25 g. per ml.solvent) at 222 C., but still contained some ash (on ignition).

The infrared absorption spectrum of the polymer showed bands as follows:

3420 GIL-1, str. broad, --OH stretch 3060 cmf wk. broad, aromatic CHstretch 2940 cm.- wk. sharp, aliphatic CH stretch 1720 cmf str. broad,C=O stretch, esters 1605 cmf str. sharp, COO--|-aromatic ring 1500 cmfwk. sharp, aromatic ring 1410 cmr med. sharp, COO- anion 1240 cm.- str.broad, CO stretch, aromatic esters 1100 cmf med. broad, CO stretch,aromatic esters The above spectrum indicates the presence of estergroups as well as carboxylate anions and suggests that the a-diketoneunits in the original polymer may have 21 reacted further to formenediol ester units which would perhaps have carboxylic acid orcarboxylate salt terminal groups on the resulting side branches.

EXAMPLE XXIV.CONVERSION OF ISOPHTHAL- OYL DICHLORIDE TO A SOLUBLEPOLYMERIC PRODUCT In an apparatus and in a manner essentially similar tothat described in Example I, 1.42 g. (7.0 millimoles) of isophthaloyldichloride, M.P. 42-44 C., in 25 ml. of redistilledN,N-dimethylacetamide was rapidly added at 70 C. to 23 ml. of a 0.925 NN,N-dimethylacetamide solution of CrCl (21.4 millimoles) also at 70 C.The resulting solution changed from blue-green to green to brown over aperiod of min. No exotherm was observed. After 2 hours at 70 C. thereaction mixture was poured into 500 ml. of water. A light, yellow-greengelatinous solid was obtained which dried to a dark green solid, 1.34 g.(143% as {-COC H CO- This solid could be dissolved inN,N-dimethylacetamide and reprecipitated with water.

While particular embodiments of this invention are shown above, it willbe understood that the invention is obviously subject to variations andmodifications without departing from its broader aspects. Moreover, thenovel polymeric products of thepresent invention are readily moldable byutilizing conventional resin molding procedures into a variety ofproducts having outstanding heat stability and radiation resistantcharacteristics.

What is claimed is:

1. A polymerization process which comprises reacting at least onehalogen-containing aromatic compound, capable of polymerization, havingthe formula wherein:

X and X are selected from the group consisting of chlorine, bromine,iodine, fluorine and mixtures thereof; R R R and R are univalentradicals selected from the group consisting of hydrogen, bromine,iodine, trifluoromethyl, lower alkyl group having from 1 to 6 carbonatoms, aryl group having 6 to 10 carbon atoms,

and mixtures thereof;

n and m are integers of at least 1;

Ar is an aromatic substituent selected from the group consisting ofarenes, aromatic heterocyclics, and fused ring aromatics with a lowervalent transition metal salt at a temperature within the range of about30 to 300 C. in the presence of a dipolar aprotic solvent having adielectric constant greater than about as the sole solvent in thereaction mixture, 'said solvent characterized by being unable to donatelabile hydrogen atoms to form strong hydrogen bonds with containedsolutes.

2. The process of claim 1 wherein said transition metal salt has acation selected from the group consisting of divalent chromium, divalentvanadium and trivalent titanium.

3. The process of claim 2 wherein said transition metal salt is chromouschloride.

4. The process of claim 1 wherein it plus m equals 2.

5. The process of claim 1 wherein said halogen-containing aromaticcompound is a,a'-dichloro-p-xylene.

6. The process of claim 1 wherein said halogen-containing aromaticcompound is 2,5-bis-(chloromethyl)-pxylene.

7. The process of claim 1 wherein said halogen-containing aromaticcompound is bis-(chloromethyl)durene.

8. The process of claim 1 wherein said halo taining aromatic compound is4,6-bis-(chloromethyl)-mxylene.

9. The process of claim 1 wherein said halogen-con- 22 taining aromaticcompound is bis-(chloromethyl)mesitylene.

10. The process of claim 1 wherein said halogen-containing compound isa,a,u',u,u'-hexachloro-p-xylene.

11. The process of claim 1 wherein said halogen-containing compound is1,2,4,5-tetrakis(bromomethyl)benzene.

12. The process of claim 1 wherein said halogen-containing compound is4,4'-bis-(a,a-dichlorobenzyl)diphenyl ether.

13. The process of claim 1 wherein said halogen-containing compound is1,4-bis-(oga-dichlorobenzyl)benzene.

14. The process of claim 1 wherein said aprotic solvent isdimethylacetamide.

15. The process of claim 1 wherein said aprotic solvent isdimethylformamide.

16. The process of claim 1 wherein said aprotic solvent is acetone.

17. The process of claim 1 wherein said aprotic solvent is acetonitrile.

18. A copolymerization process which comprises reacting a solution of(I) at least one halogen-containing compound capable ofcopolymerization, having the formula wherein X and X' are selected fromthe group consisting of chlorine, bromine, iodine, fluorine and mixturesthereof; R R and R and R are selected from the group consisting ofhydrogen, bromine, iodine, trifluoromethyl, lower alkyl group havingfrom 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, andmixtures thereof;

it and m are integers of at least 1;

Ar is a divalent arene radical, with a lower valent chromium salt with(II) an olefinic compound having the formula R5CHiR R7 wherein:

R is selected from the group consisting of hydrogen, cyano radical, andan aryl group having from 6 to 10 carbon atoms;

R; is selected from the group consisting of hydrogen, a lower alkylgroup having from 1 to 6 carbon atoms, and a COOR radical wherein R isan alkyl group having from 1 to 12 carbon atoms;

R is selected from the group consisting of hydrogen, a CN radical, a N0radical, a COOH radical, a lower alkyl having from 1 to 6 carbon atoms,a CH COOR radical and a COOR radical wherein R is a lower alkyl havingfrom 1 to 12 carbon atoms, a CONH radical, CONHR' and CONR' radicalswherein R is a lower alkyl group having from 1 to 6 carbon atoms, andan.

aryl group having 6 to 10 carbon atoms at a temperature Within the rangeof about 0 to 200 C. in the presence of a dipolar aprotic solvent havinga dielectric constant greater than about 15 as the sole solvent in thereaction mixture, said solvent characterized by being unable to donatelabile hydrogen atoms to form strong hydrogen bonds with containedsolutes.

19. The process of claim 18 wherein said chromium salt is chromouschloride.

20. The process of claim 18 wherein said copolymerization process iscarried out under a nitrogen atmosphere.

21. The process of claim 18 wherein said aprotic solvent is selectedfrom the group consisting of dimethylformamide, dimethylacetamide,acct-one, acetonitrile, dimethyl sulfoxide, tetrahydrothiophene dioxide,nitrobenzene, and propylene carbonate.

22. Poly(4,5-dimethyl-o-phenylenedimethylene).

'23 24 23. Poly(5,6-indany1enedimethy1ene). References Cited 24.Po1y(1,4-(1,2,3,4-tetrahydro)naphthylene). D PA N 25.Poly(2,4,6-trimethyl-m-Xy1ylene). UNITE STATES TE TS 26. P0ly(5,8(1,2,3,4-tetrahydro)naphthylenedimeth- 3265640 8/1966 Overhults et 2602ylene) 5 JOSEPH L. SCHOFER, Primary Examiner.

27. Poly(2,3,5,6-tetrachl'o-ro-p-phenylenedimethylene). 28.P01y(2,5-di-n-butoxy-p-phenylenedimethylene). H. WONG, AssistantExaminer.

18. A COPOLYMERIZATION POCESS WHICH COMPRISES REACTING A SOLUTION OF (1)AT LEAST ONE HALOGEN-CONTAINING COMPOUND CAPABLE OF COPOLYMERIZATION,HAVING THE FORMULA (XCR1R2)N-AR-(CR3R4X'')M WHEREIN: